Biagio Paolini

Interobserver Agreement in Immunohistochemical Evaluation of Folate Receptor Alpha (FRα) in Ovarian Cancer: A Multicentre Study

Folate receptor alpha (FRα) is a high-affinity folate transporter overexpressed in various epithelial malignancies, particularly high-grade serous ovarian carcinoma. Given its restricted expression in normal tissues and accessibility in tumors, FRα is an emerging therapeutic target. Immunohistochemistry (IHC) is the standard method for FRα assessment; however, interpretation is semi-quantitative and prone to interobserver variability. This study aimed to evaluate interobserver agreement among 12 pathologists in the IHC assessment of FRα in ovarian cancer, focusing on internal control adequacy, staining intensity, and the percentage of FRα-positive tumor cells. Thirty-seven high-grade serous ovarian carcinoma cases were stained using the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay. A reference panel of four expert pathologists established consensus diagnoses. Twelve pathologists independently assessed the slides, recording internal control adequacy, staining intensity (positive vs. negative), and percentage of FRα-positive tumor cells. Interobserver agreement was measured using Fleiss’ kappa and intraclass correlation coefficient (ICC). Agreement on internal control adequacy was almost perfect (κ = 0.84). Substantial agreement was observed for staining intensity (κ = 0.76), while percentage estimation showed almost perfect concordance (ICC = 0.89). Discrepancies were primarily confined to borderline cases (65–85% positivity) and tumors with intermediate staining, reflecting interpretive challenges near clinical decision thresholds. Pathologists demonstrated high reproducibility in FRα IHC assessment, particularly in estimating percentage positivity and control adequacy. These findings support the clinical utility of FRα IHC but underscore the need for standardized scoring criteria and potential integration of digital tools to enhance consistency, especially in borderline cases.

Malignant germ cells tumor of the ovary

Malignant ovarian germ cell tumors are rare and diverse malignancies, accounting for approximately 5% of all ovarian cancers. Primarily affecting young women, these tumors present unique challenges, particularly in balancing effective treatment with fertility preservation. Early diagnosis is common due to the rapid tumor growth and symptoms such as abdominal pain and distension, leading to favorable prognoses when combined with the high chemosensitivity of platinum-based regimens. Fertility-sparing surgery is the cornerstone of treatment for stage I disease, often followed by close surveillance to minimize the long-term toxicities of chemotherapy. Pathology is pivotal for diagnosis, incorporating immunohistochemical markers to differentiate malignant ovarian germ cell tumors subtypes, including dysgerminomas, yolk sac tumors, and immature teratomas. Advanced imaging modalities like ultrasound, magnetic resonance imaging, and computed tomography are essential for staging, monitoring treatment response, and detecting recurrences. Despite high cure rates, long-term follow-up is crucial to manage late toxicities, such as gonadal dysfunction and secondary malignancies. Recurrent malignant ovarian germ cell tumors present significant therapeutic challenges. High-dose chemotherapy with stem-cell transplantation offers promise in select cases, while the role of secondary cytoreductive surgery and radiotherapy is limited to specific indications. Emerging targeted therapies and novel approaches, such as KIT inhibitors for dysgerminomas with KIT mutations, remain experimental, with limited success reported so far. The rarity and heterogeneity of malignant ovarian germ cell tumors impede large-scale research efforts, underscoring the need for greater understanding of their molecular and genetic landscape to develop more effective and personalized therapies.

Validation of MiROvaR, a microRNA-based predictor of early relapse in early stage epithelial ovarian cancer as a new strategy to optimise patients' prognostic assessment

Early-stage epithelial ovarian cancer (eEOC) patients have a generally favorable prognosis but unpredictable recurrence. Accurate prediction of risk of relapse is still a major concern, essentially to avoid overtreatment. Our robust tissue-based miRNA signature named MiROvaR, predicting early EOC recurrence in mostly advanced-stage EOC patients, is here challenged in an independent cohort to extend its classifying ability in the early-stage EOC setting. We retrospectively selected patients who underwent comprehensive surgical staging at our institution including stages from IA to IIB. miRNA expression profile was analysed in 89 cases and MiROvaR algorithm was applied using the previously validated cut-off for patients' classification. The primary endpoint was progression-free survival (PFS) at 5 years. Complete follow-up time (median = 112 months) was also considered as secondary analysis. MiROvaR was assessable on 87 cases (19 events of disease progression) and classified 68 (78%) low-risk and 19 (22%) high-risk patients. Recurrence rate at primary end-point was 39% for high-risk patients as compared to 9.5% for low-risk ones. Accordingly, their Kaplan-Meier PFS curves were significantly different at both primary and secondary analysis (p = 0.0006 and p = 0.03, respectively). While none of the prominent clinical variables had prognostic relevance, MiROvaR significantly predicted disease recurrence at the 5-year assessment (primary endpoint analysis; HR:5.43, 95%CI:1.82-16.1, p = 0.0024; AUC = 0.78, 95%CI:0.53-0.82) and at complete follow-up time (HR:2.67, 95%CI:1.04-6.8, p = 0.041; AUC:0.68, 95%CI:0.52-0.82). We validated MiROvaR performance in identifying at diagnosis eEOC patients' at higher risk of early relapse thus enabling selection of the most effective therapeutic approach.